Reading letters and convert to numbers

[XInFisk]

Hey... I've been thinking much about how i should work this out... I want to write a script that can read a .txt file and then take the data from that file and make every letter into numbers... I mean so everytime there will come lets say an a then it'd make it to 1. and everytime there would come a b it would make it to 2 and so on... Anyone have any ideas to do this? And i don't want anyone to write the whole program, ofc not. Just how to start it.

I'd be very glad with a fast answer

-XInFisk

[Generator]

Hey... I've been thinking much about how i should work this out... I want to write a script that can read a .txt file and then take the data from that file and make every letter into numbers... I mean so everytime there will come lets say an a then it'd make it to 1. and everytime there would come a b it would make it to 2 and so on... Anyone have any ideas to do this? And i don't want anyone to write the whole program, ofc not. Just how to start it.

I'd be very glad with a fast answer

-XInFisk

FileOpen(),FileRead(),StringSplit, FileWrite() Edited April 24, 2007 by Generator

[SpookMeister]

Also you want to consider your logic, assuming you want to be able to convert it back...

How are you going to tell the difference between 24 (which could be "be") and 24 which might be "x"?

What are you going to do with numbers from the original file?

How about spaces, and punctuation (some people still use it, rare though it is)

[XInFisk]

Also you want to consider your logic, assuming you want to be able to convert it back...

How are you going to tell the difference between 24 (which could be "be") and 24 which might be "x"?

What are you going to do with numbers from the original file?

How about spaces, and punctuation (some people still use it, rare though it is)

Yeah, i've been thinking about... the numbers was just an eg.

[PsaltyDS]

Perhaps you are considering a prime number hash:

1. Assign each letter a prime number, i.e. a = 2, b = 3, c = 5, d = 7, e = 11, f = 13, etc...

2. Multiply the numbers for each letter together and you get a unique hash for that 'word', or combination of letters, i.e. 'fad' = 13 * 2 * 7 = 182

3. Factor out the primes from the hash and you will have a list of the letters in the original word (but not their position in the word).

There are more complicated versions that basic scheme to achieve many different outcomes. Which one applies depends on the application - which is...?

[XInFisk]

Perhaps you are considering a prime number hash:

1. Assign each letter a prime number, i.e. a = 2, b = 3, c = 5, d = 7, e = 11, f = 13, etc...

2. Multiply the numbers for each letter together and you get a unique hash for that 'word', or combination of letters, i.e. 'fad' = 13 * 2 * 7 = 182

3. Factor out the primes from the hash and you will have a list of the letters in the original word (but not their position in the word).

There are more complicated versions that basic scheme to achieve many different outcomes. Which one applies depends on the application - which is...?

Uhm. I'll just make this for making some text unreadable and then readable again... I'm most doing this for fun, and could be nice to show it to the friends <: So i've just been thinking about something like a = (&) and b = (/#%) and so on or something like that

[PsaltyDS]

Simple substitution cipher then:

1. Make a table of values that associates each letter with an alternate character.

2. Substitute the alternate char for the letter.

This can be made easier if you avoid the table and just throw in a little math to add/subtract a number to the ASCII code for the letter:

While 1
    $RedData = InputBox("Substitution Cipher", "Enter string to substitute: ")
    If @error Then Exit
    $BlackData = _StringSubstCipher($RedData, 3)
    MsgBox(64, "Substitution Cipher", "Substitution cipher yielded: " & @CRLF & $BlackData)
    $ClearData = _StringSubstCipher($BlackData, -3)
    MsgBox(64, "Substitution Cipher", "Substitution cipher reversed yielded: " & @CRLF & $ClearData)
WEnd

Func _StringSubstCipher($sString, $iIndex)
    Local $avSplit = StringSplit($sString, "")
    Local $RET = ""
    For $n = 1 To $avSplit[0]
        $RET &= Chr(Asc($avSplit[$n]) + $iIndex)
    Next
    Return $RET
EndFunc   ;==>_StringSubstCipher

Notice that you pass the function a number to add to the ASC() value, and deciphering is just passing the negative value for this. In the above example, the cipher is done by adding 3, and decipher by adding -3. Not very secure, but cute...

[SpookMeister]

Take a look at Asc() and Chr() in the help file. You could do some simple obfuscation with those two functions.

$file_input = @ScriptDir & "\input.txt"
$file_output = @ScriptDir & "\output.txt"

$hInput = FileOpen($file_input, 0)
$sInput = FileRead($hInput)
FileClose($hInput)
$text = ""
For $i = 1 To StringLen($sInput)
    $asc = Asc(StringMid($sInput, $i, 1))
    $chr = Chr($asc + 128) ; shift to the extended char set
    $text = $text & $chr
Next
$hOutput = FileOpen($file_output, 2) ; Write in Overwrite mode
FileWrite($hOutput, $text)
FileClose($hOutput)

; Restoring
$file_restore = @ScriptDir & "\restore.txt"
$hOutput = FileOpen($file_output, 0)
$sOutput = FileRead($hOutput)
$text = ""
For $x = 1 To StringLen($sOutput)
    $asc = Asc(StringMid($sOutput, $x, 1))
    $chr = Chr($asc - 128) ; shift back
    $text = $text & $chr
Next
$hRestore = FileOpen($file_restore, 2)
FileWrite($hRestore, $text)
FileClose($hRestore)

This is what the code above looks like when passed through the script:

¤æéìåßéîðõô ½ ÀÓãòéðôÄéò ¦ ¢Üéîðõô®ôøô¢Å ¤æéìåßïõôðõô ½ ÀÓãòéðôÄéò ¦ ¢Üïõôðõô®ôøô¢Å Å ¤èÉîðõô ½ ÆéìåÏðåæéìåßéîðõô¬ °©Å ¤óÉîðõô ½ ÆéìåÒåá䨤èÉîðõô©Å ÆéìåÃìïó娤èÉîðõô©Å ¤ôåøô ½ ¢¢Å Æïò ¤é ½ ± Ôï ÓôòéîçÌåóÉîðõô©Å   ¤áóã ½ Áóã¨ÓôòéîçÍé䨤óÉîðõô¬ ¤é¬ ±©©Å    ¤ãèò ½ Ãèò¨¤áóã « ±²¸© » óèéæô ôï ôèå åøôåîäåä ãèáò óåôÅ   ¤ôåøô ½ ¤ôåøô ¦ ¤ãèòÅ ÎåøôÅ ¤èÏõôðõô ½ ÆéìåÏðåæéìåßïõôðõô¬ ²© » ×òéôå éî Ïöåò÷òéôå íïäåÅ Æéìå×òéô娤èÏõôðõô¬ ¤ôåøô©Å ÆéìåÃìïó娤èÏõôðõô©Å Å » ÒåóôïòéîçÅ ¤æéìåßòåóôïòå ½ ÀÓãòéðôÄéò ¦ ¢Üòåóôïòå®ôøô¢Å ¤èÏõôðõô ½ ÆéìåÏðåæéìåßïõôðõô¬ °©Å ¤óÏõôðõô ½ ÆéìåÒåá䨤èÏõôðõô©Å ¤ôåøô ½ ¢¢Å Æïò ¤ø ½ ± Ôï ÓôòéîçÌåóÏõôðõô©Å     ¤áóã ½ Áóã¨ÓôòéîçÍé䨤óÏõôðõô¬ ¤ø¬ ±©©Å  ¤ãèò ½ Ãèò¨¤áóã ­ ±²¸© » óèéæô âáãëÅ   ¤ôåøô ½ ¤ôåøô ¦ ¤ãèòÅ ÎåøôÅ ¤èÒåóôïòå ½ ÆéìåÏðåæéìåßòåóôïòå¬ ²©Å Æéìå×òéô娤èÒåóôïòå¬ ¤ôåøô©Å ÆéìåÃìïó娤èÒåóôïòå©

Edited April 24, 2007 by SpookMeister

[XInFisk]

Thank you all for the replys

[phoone]

can anyone help me and tell me how to "Assign each letter a prime number".....i mean excactly....thanks

[jchd]

Each letter is a bit vague.

If you insist on "each" and take "letter" to mean "possible character, independant of AutoIt", you end up with the very large number of possible characters being defined in Unicode reference documents.

If you mean "dependant on AutoIt string representation" your target is much smaller since AutoIt can only handle 65535 distinct characters.

If you mean "english letters" then it boils down to 26. But you may have to deal with your own language using a larger number of characters (like traditional chinese).

...

You see that depending on what you actually have in mind, the answer can vary tremendously.

BTW, Unicode v5.2 currently assigns 246943 codepoints. Making a table of primes up to the 246943th is extremely easy (we have that Prime[246943] = 3450383, not a large number). But consider that using a prime hash will likely force you to use a BigInt library (there is one available for AutoIt, use search feature), even for coding the english alphabet: Apply[Times,Prime[Range[26]]] = 232862364358497360900063316880507363070

While encoding with primes can be made, decoding is a bit trickier: not only you have to routinely factor larger-than-average integers(*), but you also have to rebuild the word from the letters it contains (nothing gives you any hint regarding the order of letters).

I don't want to waste forum bandwidth posting a list of primes up to any undecent limit.

(*) integers produced by this encoding are called "smooth" which means they only have small divisors. Trial divide is the best way to factor smooth integers.

[Spiff59]

You could also mangle things up at the bit level:

#include <Array.au3>
$sStr = "This is a string"
$aStr = StringSplit($sStr, "")
_ArrayDisplay($aStr)
For $i = 1 to $aStr[0]
$aStr[$i] = BitNOT(BitRotate(Asc($aStr[$i]), 3))
Next
_ArrayDisplay($aStr)
For $i = 1 to $aStr[0]
$aStr[$i] = Chr(BitRotate(BitNOT($aStr[$i]), -3))
Next
_ArrayDisplay($aStr)

Edit: switched from code to autoit tags, formatting still not retained... what's the trick?

Edited October 26, 2011 by Spiff59

[nitekram]

why not just use the _Crypt_EncryptFile and _Crypt_DecryptFile as it already does what you want - but if not you may get some ideas from these functions